Loop-retainer for sewing-machines



(No Model.)

L.MUTHER.

LOOP RETAINER FOR SEWING MACHINES.

.No. 556,715. Patented Mar. 17, 1896.

ANDREW EGHANAIQ]. FHOYOU'MEWKSHINGTONJ C.

UNITED STATES PATENT EEicE,

LORENZ MUTHER, OF OAK PARK, ASSIGNOR TO THE UNION SPECIAL SElVINGMACHINE COMPANY, OF CIIIUAGO, ILLINOIS.

LOOP-RETAINER FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 556,715, dated March17, 1896.

Application filed July 12, 1894. Serial No. 617,345. (No model.)

To all whom it may concern.-

3e it known that I, LORENZ MUTHER, a citizen of the United States,residing at Oak Park, in the county of Cook, State of Illinois, haveinvented certain newand useful Imp rovements in Sewing-Machines, ofwhich the following is a description, reference being had to theaccompanying drawings and to the letters of reference marked thereon.

My invention relates to an improvement in sewing-machines of the generalclass illustrated in Patent No. 3%,493, dated June 29, 1886.

It has heretofore been proposed in ma chines of this character toprovide the looper near its heel with a notch on the grooved inner edgeto leave a shoulder to catch and hold the loop of the needle-thread asthe looper moves backward, thus drawing the loops of needle-thread outof the way of the needles as they again descend through the material toenter the loop of the thread carried by the looper. To prevent the loopsof needle-thread held upon the looper as the latter is retracted ordrawn backward, or out of the loops of said needle-thread, from beingdrawn forward by the strain of the thread so as to get in the path ofthe descending needles, which are about entering the loop of thelooper-thread, it has been proposed to provide the throat-plate at itsunder side and to one side of the needle-hole with a transversedepression or groove and a finger against which the loops of theneedle-thread arrive and bear as the points of the needles descendbetween the looper and the looper-thread, the outer or free end of saidfinger substantially holding the said loops until the point of thelooper in its backward movement comes to the finger, the outer end ofthe finger projccting over said depression.

I have found in practice that it the finger does not bear a certainrelation to the looper there is liability of skipping stitches, and thisnecessary relation is destroyed either by deepening the hole for thelooper-shank or otherwise setting the looper too low, or by forming thefinger a little out of proper shape or allowing it to become sprung. Itsometimes happens that the fingers are not made preciscly alike by theworkman, and therefore when put on the throat-plate do not project closeenough to the edge of the looper and thusleave space suflicient to allowthe needleloops to run oiii the looper and to be cut off by the needlesorcause stitches to be dropped.

To avoid the above objections the present invention has been made; andit consists in providing means of adjustment for said finger whereby itcan always be secured in proper position with respect to the looper, ashereinafter described and claimed.

My invention is illustrated in the accompanying drawings, in whichFigure 1 shows a longitudinal section of a portion of a cylindervamping-machine to which my invention is applied, the looper being shownas just entering the needle-thread loops, the needles moving upward.Fig. 9 is an end View showing the parts while the looper is beingretracted and the needles descending to pass between the looper and itsthread. Fig. is a detail view of a curved throat-plate, showing thefinger, the looper moving backward, and the thread; and Fig. i is abottom plan view of a flat throat-plate provided with my invention.

In the drawings, A represents a portion of the casing of a cylindervainping-machine, and B is the throat-plate thereof, the same letteralso representing the flat throat-plate shown in Fig. i.

(1 represents the looper having the usual notch forming a shoulder a,behind which in the extreme forward position of the looper theneedle-threads slip and by which they are drawn backward as the looperis retracted.

The ordinary looper-guard finger l) is provided as well as theneedle-guard c.

D is the needle-bar, herein shown as carrying the two needles d.

The throat-plate B has on its side nearest the heel of the looper ashallow transverse groove 6, and a finger f, composed of a piece of wireor other suitable material, is attached to the under side of thethroat-plate by the screw g, the point of said finger lying close to oneof the needles and extending partially over the depressed portion toleave a space between the under side of the throat-plate and point ofthe finger. This finger is preferably made of wire or spring metal; butit IOO sometimes happens that in replacing the parts the finger willbecome sprung, so that when secured to the throat-plate it will not restin proper relation to the looper, or it may be that the fingers may notbe all alike or that the looper on one machine maybe set a little lowerthan on another, in which case the ordinary finger would not perform thedesired function.

To enable the fingers to be interchangeable to adapt them to machineseven after they have been sprung and to allow for inequalities in thesetting of the looper, I provide a set-screw h, which passes through thethroatplate and bears upon the upper side of the wire, and by tighteningor loosening this screw the finger is adjusted to bring it into properrelation with the looper. The forward end of the finger is out out onits under side, as at i, to allow of the backward movement of the looperwithout danger of it striking the finger.

The operation will be easily understood from the foregoing description.In the for ward movement of the looper the needles descend and thelooper passes through the loops of the needle-threads and beyond the endof the finger. lVhen the limit of its forward movement has been reached,the loops of the needle-threads now around the looper slip into thenotch thereon, and as the looper takes its sidewise movement and goesbackward the shoulder draws the threads aside until the looper has beenretracted a portion of its distance, when the loops of the needle-threadslip from the shoulder and move toward the point of the looper. \Vhenthey reach the point of the finger, they are passed over it and held onit by the looper and between the finger and the under side of thethroatplate, while the needles descend at the rear side of the looperand between it and its thread. Then the looper reaches a point at ornear the limit of its backward movement, it releases the need le-loops,which are then drawn up into the goods over said finger.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

A throat-plate provided with a loopretaining spring-finger, securedrigidly to the throatplate, and a set-screw passing through thethroat-plate and bearing on said finger whereby the same is verticallyadjustable, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

LORENZ MUJIIER. \Vitnesses:

CHESTER MCNEIL, lllARTIN MCNEIL.

